1. Field of the Invention
This invention relates in general to the production of edible wafers from wafer dough, which in most cases is liquid and is introduced into the wafer baking molds of wafer baking tongs and is baked to form the wafers in a wafer baking oven or an automatic wafer baking machine. More specifically, the invention relates to wafer baking tongs which consist of two tong parts, which are provided with the baking mold parts of the wafer baking tongs. Said baking mold parts have confronting baking surfaces, which define the three-dimensional shape of the baked wafers. Said baking mold parts may be integrally formed with the respective tong parts. To permit the wafer baking tongs to be opened and closed the two tong parts of a pair of wafer baking tongs are designed to be pivotally movable toward and away from each other about a common axis or to be linearly movable toward and away from each other.
2. Description of the Prior Art
In the wafer-making industry, wafer baking tongs are used in wafer baking machines or automatic wafer baking machines for a mechanical production of individual wafers or wafer products having a predetermined three-dimensional shape in large quantities. As a rule, a wafer baking machine comprises 24 to 80 identically designed pairs of baking tongs, which are arranged in a row and interconnected to form a chain of pairs of baking tongs and revolve through an oven-chamber from a dough feeding station to a wafer product discharge station. Modern wafer baking ovens or automatic wafer baking machines have been described, e.g., in U.S. Pat. Nos. 4,417,508; 4,438,685; and 4,648,314.
Just as in a confectionary, a distinction is made in the wafer industry between crisp, brittle, fragile wafer products, which in the final product have a moisture content not in excess of 1 to 4%, and soft, elastic wafers, which in the final product contain moisture in excess of 8%.
Examples of crisp, brittle wafer products baked in wafer baking ovens or wafer baking machines consist of cast wafer cones, large rectangular wafer sheets, low hollow wafers, wafer cups, wafer plates, and cast wafer figures. Such products are usually baked from a liquid dough or from a wafer dough which contains no sugar or has only a low sugar content.
Another known crisp, brittle wafer products made in wafer baking ovens or wafers baking machines is the rolled wafer cone, which is also known as an ice cone or sugar cone and is made in that a wafer sheet or flat wafer cake is baked from a liquid wafer dough having a high sugar content and is rolled up to form a cone while the wafer is still in a warm, plastically deformable state.
An example of soft elastic wafers is constituted by the so-called Belgian wafers, which are baked from a wafer dough which contains a raising agent and 20 to 50% egg material.
The wafer products mentioned hereinbefore are produced with the aid of wafer baking molds, in which a single piece of wafer product or a plurality of wafer product pieces, depending on the nature of the wafer product, are baked at a time. For instance, large crisp, rectangular wafer sheets are individually baked in wafer baking molds which comprise two baking plates each. On the other hand, crisp wafer cones are baked in sets of, e.g., six cones in a single wafer baking mold.
In known wafer baking tongs for making wafers or wafer products, such as flat wafers or low hollow wafers or the like, the baking surfaces are formed on the inside surfaces of two flat baking plates, which are laterally provided with ledges, which laterally seal the cavity defined by the wafer baking mold when it is closed. When that wafer baking mold is closed, the single parting plane thereof is disposed between and parallel to the two baking plates, which have confronting baking surfaces and are received or integrated in two tong parts, which are connected by hinge means on one side and can be pivoted between closed and open positions and on that side which is opposite to the hinge means are provided each with a closure section for rigidly interlocking the tong parts when they have been pivoted to a closed position so as to close the wafer baking mold.
If the wafer baking mold is separated from the baking tongs, the two tong parts of the baking tongs constitute carrying frames which can be pivotally collapsed and unfolded and in which the closure sections and the hinge means of the baking tongs are integrated and which take up the pressure forces which during the baking process act on those baking mold parts which are received by the tong parts and consist, e.g., of the two baking plates.
If the wafer baking mold is integrated in the baking tongs, the parts of the baking mold, e.g., the two baking plates, constitute self-supporting parts of the baking tongs and particularly of the two tong parts and in that case the hinge means of the baking tongs and the closure sections of the baking tongs are formed on components which are laterally attached to the baking plates.
For use in the production of hollow wafers, such as cast crisp wafer cones or wafers figures or the like, the wafer baking mold that is received in two parts consists of a punch that is received in one tong part and a die, which is formed with molding recesses and is separated from the punch along a parting plane and consists of two die halves, which are separated along a second parting plane that is separate from the first, and the mold also comprises an opening and closing mechanism and is received in its entirety in the other tong part.
In known wafer baking tongs each of such wafer baking molds consisting of a punch and die is received in two tong parts, which are adapted to be pivotally collapsed and unfolded and are connected on one side by hinge means, and each of said tong parts is provided on that side which is opposite to the hinge means with a closure section for rigidly interlocking the tong parts when they have been collapsed to close the wafer baking mold.
Other known wafer baking tongs comprise two of such wafer baking molds, each of which consists of a punch and die and is received in two tongs parts, which are adapted to be moved toward and away from each other and are movable along track rods and are provided on each of two mutually opposite sides with two closure sections, which constitute pairs of mutually opposite closure sections for rigidly interlocking the two tong parts when they have been collapsed to close the two wafer-baking molds.
In the known wafer baking tongs the closure sections provided on the tong parts and cooperating to rigidly interlock the two tong parts have different shapes. The two closure sections togeter constitute the closure of the baking tongs and said closure is actuated when the baking tongs are closed at the beginning of the baking time and when the baking tongs are opened at the end of the baking time. If the baking time amounts to 1.5 minutes and the wafer baking machine is operated for 14 hours per day, the closure will be actuated 1120 times a day.
Known wafer baking tongs comprise a rotatable locking mandrel in the closure section of one tong part and a rigid locking plate on the closure section of the other tong part. The locking mandrel is rotatably mounted in the closure section of the lower tong part and is substantially at right angles to the parting plane of the baking mold and at its end portion upwardly protruding from the inside surface of the closure sections carries a hammer head, and a rotary star wheel is non-rotatably secured to the downwardly protruding end portion of said mandrel. The locking plate is provided with a slot, through which the hammer head of the locking mandrel is adapted to move. The locking plate is secured to two spaced apart extensions, which protrude from the closure section of the upper tong part and leave a sufficiently large gap between them for a rotation of the hammer head. When it is desired to interlock the two tong parts after the hammer head of the locking mandrel has moved through the slot in the locking plate, the locking mandrel is rotated until the underside of the hammer head rests on the upper surface of the locking plate. When the locking plate has been worn in operation, that wear is compensated by a replacement of a washer, which is disposed between the inside surface of the closure section and a collar of the locking mandrel. That washer is machined to have the height that is required in a given case.
Other known wafer baking tongs comprise carrying frames and baking plates received in said frames and the closure section of the upper part of said tongs protrudes from that tong part substantially at right angles thereto toward the parting plane of the baking mold and contains a cylindrical bore, which is parallel to the parting plane and in the closed baking tongs is aligned with a cylindrical pin, which is mounted in the closure section of the lower tong part, which closure section protrudes substantially at right angles to the parting plane, and said locking pin is mounted in said closure section for a displacement that is parallel to the parting plane. When the two tong parts are to be interlocked, the pin is pushed into the bore.
In further known baking tongs a hook is pivoted to one tong part on an axis that is parallel to the parting plane and said hook is movable from the outside in a lateral direction into the closure section of the other tong part.
In all said known closures the wear which takes place in operation in the bearing means for the movable locking elements will result in a larger bearing clearance so that the baked wafers increase in thickness.